Identification and sequence analysis of a gene encoding gp67, an abundant envelope glycoprotein of the baculovirus Autographa californica nuclear polyhedrosis virus.

Monoclonal antibodies with specificity for the abundant envelope surface glycoprotein (gp67) of Autographa californica nuclear polyhedrosis virus (AcMNPV) were used to screen a lambda gt11 expression library of AcMNPV DNA fragments. The gp67 gene was mapped to the left end of the EcoRI H fragment in a right-to-left orientation on the consensus map of AcMNPV. A 2.1-kilobase transcript which hybridized to the region was first detected in cell extracts at 2 h postinfection; it peaked in abundance at 18 h postinfection and thereafter was present at lower levels. The nucleotide sequence of the region was determined, and a 1,590-nucleotide open reading frame flanked by an AT-rich sequence was identified that could encode a polypeptide with 529 amino acid residues (molecular mass of 60,167 daltons). Computer analysis indicated that the peptide possesses two hydrophobic regions near the N and C termini as well as six potential N-linked glycosylation sites. We suggest that following cleavage of a signal peptide, the polypeptide undergoes further processing and becomes anchored at its C terminus in the virus envelope. The final seven amino acid residues at the C terminus contain basic amino acids and may have a role in virion assembly.